# Limitations of MySQL Syntax Support

__*Limitations of MySQL syntax support*__
__*MySQL syntax compatibility*__

+ Features not supported:
  + Stored procedures and function
  + triggers
  + Foreign keys
  + function
  + ...
-------------------------------------------------------------
Features not supported
- Stored procedures and function
- triggers
- occurrences
- Custom function
- foreign key constraints
- Temporary tables
- Full Article/Spatial function and Indexes
- Non-ascii/latin1/binary/utf8/utf8mb4 character sets
- SYS schema
- MySQL trace optimizer
- XML function
- X-Protocol
- Savepoints
- Column-level privilege
- XA syntax (TiDB uses a 2-phase commit internally, but it is not exposed through the SQL interface)
- CREATE TABLE tblName AS SELECT stmt syntax
- CHECK TABLE syntax
- CHECKSUM TABLE syntax
- GET*Lock and RELEASE*LOCK function

For details, please refer to: https://docs.pingcap.com/zh/tidb/stable/mysql-compatibility